VIENNA (AFP) - EU Energy Commissioner Guenther Oettinger warned on Monday that the bloc may face gas shortages this winter after Russia cut supplies to Ukraine following the collapse of talks.

"The next weeks will not be a problem, we will receive our gas volumes," Oettinger said in Vienna, cautioning that if Ukraine uses its reserves "then we would have a problem with a cold winter".

Ukraine, like other countries, holds gas stockpiles it can tap to ensure gas continues to flow to Gazprom customers in the EU even if there are problems with supplies from Russia.

But Ukraine could, as it has during previous disputes, also tap these reserves and use the gas for its own needs, potentially threatening supplies to the EU.

The nation of 46 million people receives half its gas from Russia and transports 15 percent of the fuel consumed in Europe.

Two months into a violent feud that has provoked the worst conflict between Russia and the West since the Cold War, Ukraine on Sunday failed to broker an 11th-hour deal on future gas supplies with state-owned Russian giant Gazprom.

Compounding Kiev's problems as it confronts an insurgency in the east, Gazprom on Monday halted deliveries and started a new regime that requires Ukraine to pay in advance for gas supplies.

Gazprom said it had notified Europe of possible gas disruption and lodged a US$4.5 billion (S$5.6 billion) lawsuit against Ukraine with an arbitration court in Stockholm.

Gazprom stressed, however, that for now gas for European clients was flowing via Ukraine without interruption, and Ukraine has vowed to continue transit shipments to the European Union.